KAMAKURA, Kanagawa Pref. — The truck farmers market in the center of this ancient capital has been an experiment on many fronts: It is a rare no-middleman link to consumers, engaging in a communal shared rotation of stalls and offering an ever-expanding bounty to please the city’s worldly palates.

These farmers now worry that they are becoming part of an experiment themselves.

The city plans to plop a food waste recycling plant in their midst. The plan is to extract biofuel from fermented food waste. No incineration, no dioxin, no chemical risks, the city assures.

The market’s standard seasonal staples are just for starters on a produce list that reads like a who’s who of must-have items virtually unavailable elsewhere in Japan, even at the most high-end Western-style supermarkets.

In fact, go to a supermarket anywhere and chances are the produce has been trucked in from another, far-flung part of the country or imported, but rarely local, and rarer still, not via middlemen.

These variations on long-standing staples have been a process of experimentation as the farmers seek to accommodate wider, cosmopolitan tastes. And they test these edibles in a tight, humanity-encircled area, gambling with limited space where they could otherwise play it safe with standard staples.

The farmers not only sell this produce, much of it organic, direct to consumers, but also offer neophytes ways to prepare the fare. Watch as a sun-hardened, -dried tiller of the soil snaps off a green leaf and offers it raw and fresh to sample.

“I don’t know what they’re called,” a longtime female vendor said, stuffing a bag with Brussels sprouts. “Someone asked me to try growing them, and I did. I guess you can boil them.”

The market is not just a source of local produce for area households but also for Kamakura’s restaurants.

One, an Italian joint, works a patch among the farmers. It can’t get any fresher than that. A local small French eatery also boasts Kamakura-grown greens on its menu.

But now the farmers, many representing generations of the same families working the same patches, feel they are about to be part of a local-government environmental experiment via the untested food waste recycling plant.

The farmers sense a foul scent, in part because they learned about the plan in the newspaper, not directly from Kamakura officials.

They also worry, well, about the smell of rotting produce, and of the 40 or so daily round-trips by trash haulers on the access road, runoff if weather or other factors foul up the operation, and the impact such a facility will have on their image.

The farmers recall feeling misled by the city in the past, in one incident in which some purchased cropland only to find out the topsoil was reportedly a cover over a former trash dump. Produce grown in that patch stank and didn’t sell.

“We have those problems behind us,” said Kaneo Yamamori, a farmer of 30 years who represents some 50 members opposing the plant. “Because of this, we couldn’t plant rice paddies there anymore.”

The farmers launched a petition drive last fall to block the plant, but also as a way to get the city to sit down with them and talk in earnest, and not merely decide their fate behind closed doors.

At present, the project is proceeding in low gear in part because of ongoing negotiations with the farmers, and also because the decision has yet to be made on purchasing the property for the plant.

Unlike the rest of the metropolis that has crowded around them with rampant development of bedroom communities for salarymen and women commuting to offices elsewhere, Kamakura’s truck farmers make their living off their land and its yield, leaving their lot up to the weather and all the other twists of fate that can make or dash their chances.

So, too, are the farmers vulnerable to fickle consumer tastes — tastes easily swayed by media reports of crop contamination both nearby or far away. Any bad news can be devastating for business.

“The nature of a rumor is that once it takes its toll, it becomes a matter of life and death for farmers,” was how the Kamakura Association for the Protection of Vegetables, a planters group, put it recently. “Our opposition grew from a central theme: We want to work our broad tract of land . . . with confidence.”

But is this a case of Old Green versus New Green?

The city, which has an incinerator plant, maintains that the planned processing plant will not only help alleviate the local trash problem but also yield clean biofuel.

“It’s about being a zero waste society,” said Masayuki Kakizaki, the Kamakura municipal official in charge of monitoring construction.

“Without resorting to incineration, we want to exploit biomass through the process of fermentation in a bid to reduce the burden on the environment and cut carbon dioxide (emissions) and thereby prevent global warming.”

Much of the farmers’ wariness stems from a scandal just little more than a decade ago in which there were reports that gas emissions caused by the slipshod burial of incinerated ash under soil parceled to farmers might have caused discoloration of produce, giving some vegetables a foul odor.

The city conducted a probe but concluded the problem may have been caused by buried fertilizer, not incinerated ash.

It is fitting that the farmers still raise the specter of incineration when voicing their grievance, for burning garbage is very much at the center of the debate.

Japan has drawn criticism from environmentalists for its longtime policy of incinerating some 80 percent of its garbage. Concerns about the ash produced by the process are one thing, but greenhouse gases are another.

Although today many impurities are removed from smoke before it passes through the flues of Japan’s high-tech incineration plants, a considerable amount of carbon dioxide is nonetheless released into the atmosphere.

Kamakura, with a tall white incinerator smokestack not far from the center of town, says its planned biogas plant is aimed at helping it break its smoking habit, cutting the amount of garbage being incinerated or used as landfill “as close to zero as we can get.” Officials hope to construct the plant and begin operations by March 2013.

The planned three-story facility, tentatively called the Bio Recycling Center and slated for a site in the city’s northwest, would process some 80 tons of garbage a day, converting it by fermentation into energy-rich methane gas.

That gas would in turn be burned as a fuel, yielding enough electricity to power 1,000 homes without using petroleum or coal, the city said.

Burning biogas only releases as much carbon dioxide as was consumed by the plants and animals whose remains ended up as fuel.

Kamakura’s biogas initiative is in line with a broad effort by the central government to keep its Kyoto Protocol promise to slash carbon emissions by 13 percent by 2012.

Nationwide, there are already 451 plants producing fuel from biodegradable waste, according to Kamakura.

But as green as Kamakura’s plan may appear to be, farmers worry that exhaust from the 40 truckloads of raw garbage hauled to the plant, or byproducts from the processing itself, could taint their crops. Even the city acknowledges the facility would be closer to populated areas than its forerunners.

Kamakura official Kakizaki said that because the fleet of garbage trucks is held to stringent vehicle-fuel standards, there is little concern of exhaust contamination. What’s more, he said, with 3,000 private vehicles already in the vicinity, the trucks would increase total exhaust by less than 2 percent.

Fellow official Naomi Takenouchi said sludge from the fermentation process will be taken to an incinerator in neighboring Zushi if negotiations there work out. And impurities in runoff water will be cut to acceptable levels before being emptied into either rivers or sewer pipes.

“We are looking at ways to maintain every standard,” she said.

Since the petition drive started, the farmers have accumulated more than 21,000 signatures and started open discussions with the city. They hope that, like their crops, their efforts bear fruit.

Spring is afoot and they want to focus on what they do best: till the soil and bring their bounty to market. As one longtime vendor shouts it, anytime it’s her designated day to sell, and as anyone within earshot of the market will testify, “irrashaimase” (welcome). Her refrain tells it all.